Envelope



July 20,1937. J. D. LANE ET AL ENVELOPE Filed Nov. 2, 1934 7a Zk/za MM Patented July 2%,, 1937 NT @FFEQE ENvELorE John in. Lane, Boston, and Ralph n. Wilbur, Melrose, Mass; said Lane assignor to said Wilbur Application November 2, 1934, Serial No. 751,118

This invention relates to an envelope for mailing or similar purposes whose front is equipped with a projecting flap adapted to overlap its back and be sealed thereto. As heretofore made, the flap carries a coating which is capable of undergoing adhesive activation by a moistening liquid, the usual coating being water-soluble glue such as can be activated by water or saliva. The sealing of such envelopes hence involves a moistening operation by the sender, which operation is not only time consuming and expensive in business houses sending out considerable mail, advertising literature, or the like, but which, unless water or a moistening instrument is handy, re-

quires the sender to indulge in the distasteful and unsanitary pastime of licking the flap.

The present invention affords an envelope which requires no moistening operation in its sealing despite the fact that sealing is done by bringing the envelope flap into overlapping contact with the back of the envelope, as usual, Wherefore, the envelope of the present invention overcomes those faults inhering in the conventional envelope of' the prior art without any substantial change in the mode of using the envelope, that is, any change that would require teaching people new ways with the usual prejudice apt to arise thereagainst. Generally speaking, the envelope of the present invention is like that of the prior art in that it is equipped with a front and back and a flap projecting from the front and adapted to overlap and be sealed to the back, but, rather than coating merely the flap with a composition that requires a moistening liquid for adhesive activation, both the flap and the area of the back adapted to be overlapped thereby are coated with a composition of a nonadhesive but firmly cohesive character, whereby, when the coated flap area is brought, without any treatment whatever, into contact with the coated back area under only slight or ordinary pressure, the envelope is properly sealed. The envelopes of the present invention may be readily packaged as a plurality of superposed or adjacent units, each envelope or unit being separately or individually removable from a package as needed, by keeping the coated flap of each envelope in a package out of contact with the coated area of the back of the corresponding envelope and out of contact with the coated flap and the coated area of the back of an adjacent envelope. The present invention thus comprehends not only a novel form of envelope but also a package of a plurality of the novel envelopes.

With the foregoing and-other features and objectives in view, We shall describe our invention in further detail with reference to theaccom panying drawing wherein:

Figure 1 represents a plan view of the back side of an envelope embodying our invention.

Figure 2 is a section on the line of 22 of Figure 1.

Figure 3 shows in perspective a package of the envelopes of Figure 1.

Figure 4 is a section on the line lt of Figure 3 of the top envelope in the package.

Figure 5 is a plan view of the back side of another and preferred form of envelope embodying our invention.

Figure 6 shows in perspective a package of the envelopes of Figure 5.

Figure '7! is a plan view of the back of still another form of envelope embodying our invention.

Figure 8 shows in perspective a package of the envelopes of Figure 7.

The envelope shown in Figure 1 is of a construction and shape with which everybody is familiar so that we need not describe it in detail excepting to say that it is fabricated from a single blank of paper and includes a front in, a back I l,

and a flap l2 projecting beyond the upper edge of the front and adapted to overlap the back. Pursuant to our invention, the flap carries a coating iii of the desired composition on its inner marginal area; and the back carries a coating M of similar composition on so much of its outer marginal area as is to lie under the coating I3. Inasmuch as the coatings l3 and M are cohesive, when the flap i2 is brought down into sealing relationship with the back of the envelope, as illustrated in dotted outline in Figure 2, the flap becomes sealed to the back by virtue of the firm coherence of the two coatings. However, such desirable sealing of the envelope does not mean that a plurality of such envelopes cannot be put into package form, for, the coatings l3 and it are of a non-adhesive nature and do not tend to stick to uncoated envelope areas or to other uncoated objects with which they contact. Thus, when the flap I2 is tucked inside the envelope, as best shown in Figure 4, and a number of the envelopes are piled up into a package, asdepicted in Figure 3, no trouble is encountered in maintaining the envelopes as separate units, since, in such package, coated envelope areas are in contact with uncoated envelope areas to which they have no,

tendency to adhere.

The preferred embodiment of our envelope shown in Figure 5 is also fabricated from a single It is because the form of envelope shown in Figure 5 can easily be closed without sealing for r blankof paper and is equipped with a flap l5. adapted to overlap and be sealed to the back.

In lieu of-the conventional envelope back, however, the back is formed up from a pair of wings iii of relatively narrow width extending from the opposite side edges of the front I! and a back back member 18 so as topermit easy closing of the envelope for packaging, as shown in Figure 6. The appropriate coating may be on the inner marginal area iii of the flap l5 and on the outer marginal area. 20 of the back member i8, such disposition of the coatings comporting with a maintenance of the envelopes in the desired unsealed and-individualized condition in a package.

packaging purposes and because it can easily be opened for use that it constitutes the preferred embodiment of our invention. This envelope is,

of course, sealed by bringing the flap i5 down over the back member i8 and pressing it thereto, the coating on the area I9 thus-being, made to overlie and become firmly coherent to the coating 20 on the back member.

The form of envelope shown in Figure '7 is similar to that shown in Figure 5 excepting that the flap I5 is coated on its outer marginal area 2l and the back member i8 on its inner marginal area 22, that is, a zone on its unsecured upper edge portion. This form of envelope is more easily packaged thanthat shown in Figure 5,-

since packaging is performed with-the flap l5 overlying the back member l8, as shown in Figure 8. However, inasmuch as the sealingof the envelope of Figure '7 requires the insertion of the flap I5 in between the unsecured upper edge portion of the back member l8 and the wings l6 so as to bring the coated area 2| into contact with the coated. area 22 rather than the usual and natural one of merely bringing the flap down over the back of the envelope, we regard the form of envelope shown in Figure 7 as not being as desirable as that of Figure 5.

There are various coating compositions that may be used to produce the localized coatings necessary on the envelopes of the present invention. Generally speaking, such coating compositions comprise solutions or dispersions of an elastic substance, such as rubber, which are applied in fluent state to the appropriate envelope areas and permitted to dry or set thereon. We have found that rubber latex compositions are I, especially suitable for the purposes of our invention, since they are aqueous compositions which may be readily applied and dried on paper envelopes to deposit the desired localized rubber coatings which have no adhesive amnity for uncoated paper or other uncoated bodies but which, when brought together, cohere with the desired tenacity or bond. The ordinary rubber laticesof commerce, for instance, ammonia-preserved latex of normal solids content, say, of'about 30% to 35% solids content, diluted rubber latices, or so-called concentrated rubber latices of much higher than normal solidscontent may be employed. If desired, the rubber latex may be compounded with various agents, such as fillers, vulcaniging ingredients, glycerine, or other agents designed to rubber solutions as the coating compositions, we

prefer to compound therewith so-called anti-oxidants, as these tend to preserve the dry rubber coatings deposited from the compositions in,a

stable or unoxidized condition, that, is to prevent In all instances when we use aqueous rubber dispersions, rubber latices, or

such. coatings from becoming more or less brittle and progressively losing their cohesive qualities as they are aged or exposed to atmospheric influ- In some instances, there may be a tendency.

for the coated area, on the flap. and/or the coated unsecured area on the back of the envelope to cockle or curl after thecoating composition has, been applied and then 'set' or dried. Such cockling or curling is apt to take place more especially when aqueous coating compositions, such as hereinbefore described, are applied toa relatively thin and highly flexible paper base in comparatively dilute condition, that is, at high water content, in consequence of which water may penetrate into the paper base and develop shrinking stresses therein as it is being dried, with accompanying cockling or curling thereof. If, under the foregoing circumstances, the coated areas of the envelope have become so badly cockled or curled as to interfere with satisfactory handling,

packaging, or sealing of the envelope, the cockle or curl may be readily removed by subjecting the coated areas to an'i'ndenting or' corrugating operation designed to produce therein ribs, corrugations, 'or otherlocally offset areas that straighten out and stiffen the coated areas as a whole and thereby destroy such cockling or curling as has taken'place'and inhibit any further undesirable cockling or curling. r

We claim:-

1. An envelope fabricated from a single blank.

of paper'and equipped with a frontand back thereto except at a substantially unfolded'upperedge portion whose upper edge occurs consider ably below the upper edge of the front, said flap being 'insertible and maintainable in between said wings andsa'id unsecured upper edge portion and said flap and said unsecured upper edge and a flap projecting from the-front and adapted portion being coated on one pair of their faces capable of being brought into overlapping contact with a composition ofa non-adhesive but firmly cohesive character, at least one of said other pair of faces bein'guncoated with said composition, whereby said envelope may be. packed with overlapping by said flap of said upper edge portion at said uncoated face and thus withno sealing of said envelope and, on the other hand, said envelope may be sealed with overlapping by said flap of said upper edge portion at said pair of coated faces.

2. An envelope fabricated from a single .blank 5 of paper and equipped with a front-and back" and a flap projecting from the front and adapted to overlap and be sealed to the back, said'back being formed up from a pair of wings extending from opposite side edges of said front and a back member extending from the'lower edge of said front over said wings and adhesively secured thereto except at a substantiallyunfolded upper edge portion whose upper edge occurs considerably below the upper edge of the front, said flap being insertible and maintainable in between said wings and said unsecured upper edge portion and said flap being coated on its inner face and said unsecured upper edge portion being coated on its outer face with a composition of a non-adhesive but firmly cohesive character, at least one of said other pair of faces afforded by said flap and said upper edge portion being unportion.

coated with said composition, whereby said envelope may be packed with the outer face of said flap overlapping the inner face of said upper edge portion without sealing said envelope, whereas, on the other hand, said envelope may be sealed with the coated inner face of said flap overlapping the coated outer face of said upper edge JOHN D. LANE. RALPH H. WILBUR. 

